Aim of the study: The odontogenic sinusitis has an incidence between 38 and 40.6%. Increased risk of maxillary sinusitis has been reported with the presence of periapical abscesses, periodontal disease, dental trauma, tooth extraction and implant placement when the sinusal membrane is perforated.
Materials and methods: A patient with odontogenic maxillary sinusitis associated with oro-nasal fistula was treated.
Results: The follow-up at six months showed the complete resolution of maxillary sinusitis, palatal fistula got closed and pain symptoms disappeared.
Conclusion: This case report describes a rare complication of odontogenic maxillary sinusitis: the oro-nasal fistula.
Keywords: maxillary sinusitis; odontogenic sinusitis; oro-antral fistula; oro-nasal fistula.